Watch: Great Barrier Reef at risk of dying within 20 years

Mass bleaching has destroyed as much as 35 percent of the coral on the northern and central Great Barrier Reef Australian scientists said on Monday a major blow to the World Heritage Site that attracts abou $3.59 billion in tourism each year Australian scientists said in March just seven percent of the entire Great Barrier Reef had avoided any damage as a result of bleaching, and they held grave fears particularly for coral on the northern reef